UI Design Newsletter – June, 2003

A significant effort is currently directed toward the challenges of creating effective Web designs for older individuals. Publications such as the National Institute of Aging's Checklist, "Making your Website Senior Friendly," provide detailed guidelines for creating Web sites that match the needs and sensory challenges of older individuals.

Old enough to notice

But what is the definition of "senior" when we are talking about people using computers? When do the sensory and perceptual indicators change? Do they change all at once? The research shows that the sensory changes that are typically associated with old age are really the result of a gradual sensory decline that begins earlier than we usually think – typically between the ages of 40 to 55 – well before people consider themselves "old." Recognition of this continuum of development is reflected in the age categorization of individuals across various research studies. Bailey (2002) cites a variety of research in which the "old age" categories vary broadly, including one study in which "older users" were defined as "over 58" (Study 1), "over 40" (Study 2) and "over 50" (Study 3, Charness and Dijkstra, 1999).

Understanding the onset and trajectory of sensory change throughout middle adulthood is important information for Web designers, since the middle-aged / baby-boomer population represents a large and connected user group: According to the UCLA Internet Project Report (Year 3), roughly 73% of individuals in the middle age bracket(s) access the Web. In addition, this age group represents the first generation for whom the Internet represents a core career tool.

• 90.2% of individuals use the Net for business (60.5 report using it for personal reasons).
• 90.6% of respondents reported that the Internet is moderately, very, or extremely important as an information source.
• 64.5% reported that access to the Internet made them somewhat more, or much more productive.

What's changing?

Declines in visual and auditory acuity are small and gradual from early to middle adulthood. However, the accumulated effect is that these changes are noticeable by the mid forties.

Several types of physical changes take place in the eye during this time. They may include:

• corneal flattening which reduces the amount of light that passes into the visual processing system,
• reduced lens elasticity which reduces focusing power and, consequently reduced visual acuity. This change gives rise to feeling of "tired eyes,"
• visual field reduction resulting in an inability to "see" information on the outer edge of a site or visual array,
• reduced retinal efficiency resulting in a diminished ability to adapt to glare or changing light conditions – a condition that is critical to both human computer interactions and driving, and finally,
• loss of near vision, resulting in the need for the dreaded bifocals. (Note that the average distance from the eyes to the monitor falls neither in the near vision or far vision range of most bifocals – although we spend a significant amount of time looking at a screen, only a small subset of users have glasses that optimize visual acuity for that specific, high frequency activity.)

While any of these gradual changes individually might not result in a noticeable difference in the user experience, taken together they may have a cumulative effect that makes information processing more difficult. Further, they may result in "knockoff effects," in which the cognitive effort required to do sensory processing diminishes the available resources remaining to engage in deeper, interpretive processing of the information.

What does this mean?

Designers have become sensitized to the differing needs of the aging population. Now we need to reinforce the understanding that sensory changes across the adult lifespan reflect a gradual, continuous change. There is a difference between 20-something eyes and 40-something eyes. As such, invoking basic design principles such as maximizing the text/background contrast in critical content areas will improve the sites usability for both younger and older users. Creating engaging and clean designs that effectively balance color and white space to create a visual hierarchy that serves to guide the users' gaze will provide the same benefit to younger users that it does for older adults.

References

Making your WebSite Senior Friendly (National Institute of Aging)

UCLA Internet Project Report – Year 3

Charness, N. and Dijkstra, K. (1999), Age, luminance, and print legibility in homes, offices, and public places, Human Factors, 41(2), 173-193.

Unless designing an X-Generation site, keep your font sizes a bit bigger (12 to 14pt). Also, be extra careful about low color contrast and backgrounds that interfere with legibility.

In addition, I would suggest that functionality, presentation, and content needs to be aligned with the older population. We have a whole field (I18N) where we adjust applications and sites to different cultural contexts. Just so, I suggest that we need a set of similar approaches to adjust offerings that are targeted to an older population. If you need a good example of this type of alignment, simply read the magazine of the AARP. I do get that now... Sigh